The present invention relates to an apparatus and method for mounting an optical element. More specifically, the invention provides a support structure for utilization when mounting the optical element on a mounting plate.
Currently, it is possible to mount standardized, commercially available optical elements to a mounting plate. These optical elements may be, for example, wave length division multiplexers (WDM) or couplers that are mounted to the mounting plate and then installed in a larger optical unit, such as a repeater. When utilizing these standardized, commercially available optical elements, the mounting plate and the optical element may not optimally mate. If the optical element and the mounting plate do not mate properly, it is possible that the optical element could be deleteriously impacted. For example, the optical element could loosen from the mounting plate and thus possibly become damaged as a result.
FIG. 1 illustrates a known optical element 100 that is to be mounted to a mounting plate 200, which is illustrated in FIG. 2. Optical element 100 could be any of a variety of elements, one of which may be the wave length division multiplexer mentioned above available, for example from Corning. Optical element 100 includes an input fiber 10 and an output fiber 20 for carrying optical signals through optical element 100. Optical element 100 includes a casing 101, within which is contained the optical component, e.g., the WDM mentioned above. Casing 101 has four mounting tabs, namely tabs 102, 104, 106, and 108, which define apertures 102A, 104A, 106A, and 108A, respectively. The mounting tabs receive connection hardware therethrough to mount optical element 100 to mounting plate 200.
FIG. 2 illustrates a known mounting plate 200. Mounting plate 200 also includes four mounting tabs 202, 204, 206, and 208. The mounting tabs on mounting plate 200 align with the mounting tabs on optical element 100 when optical element 100 is positioned onto mounting plate 200 for mounting of the optical element to the mounting plate. Mounting tabs 202, 204, 206, and 208 each include a threaded insert 202A, 204A, 206A, and 208A, respectively, within them. The threaded inserts are positioned within the apertures defined by the mounting tabs and may be retained within the mounting tabs by utilizing an adhesive.
FIGS. 3 and 4 illustrate a prior art arrangement for mounting optical element 100 to mounting plate 200. As can be seen, optical element 100 is positioned and aligned on mounting plate 200 such that mounting tabs 102, 104, 106, and 108 of optical element 100 align with mounting tabs 202, 204, 206, and 208 of mounting plate 200, respectively. Mounting hardware, e.g., a screw, is received within the aligned mounting tabs to secure optical element 100 to mounting plate 200. As such, screw 302 is received within tabs 102 and 202, screw 304 is received within tabs 104 and 204, screw 306 within tabs 106 and 206, and screw 308 within tabs 108 and 208. A threaded end of each screw threadedly engages with the threaded insert included in each mounting tab in mounting plate 200 to secure optical element 100 to mounting plate 200.
However, at least one drawback exists with the currently known method for mounting optical element 100 to mounting plate 200. Whereas FIG. 5 illustrates the arrangement of one mounting tab of optical element 100 and one mounting tab of mounting plate 200, all of the mounting tabs of optical element 100 and mounting plate 200 are similarly configured, as described above, and thus the same drawback discussed below is associated with each set of mounting tabs. As can be seen in FIG. 5, mounting tab 104 of optical element 100 includes an inner taper 104B. As screw 304 is threaded into threaded insert 204A of mounting tab 204 on mounting plate 200, threaded insert 204A is susceptible to being pulled out of mounting tab 204 in reaction to the downward threading of screw 304 into threaded insert 204A. If threaded insert 204A is pulled out of tab 204, threaded insert 204A would tend to move upward in the direction of the arrows shown in FIG. 5. This upward movement of threaded insert 204A could result in the threaded insert applying pressure upward against the tapered walls 104B of tab 104 of optical element 100. This upward force could result in cracking and splitting of the mounting tabs and casing of the optical element, thus rendering the optical element useless since it can no longer be secured to the mounting plate.
One reason that the mounting tabs of the casing of the optical element may be formed with the tapered inner surface is to assist in the manufacturing of the casing. When these casings are formed in a mold, the tapered surface in the mounting tab allows the finished molded part to be more easily removed from the mold. The tapered surface within the tab provides for less friction and adhesion between the mold structure and the finished molded part when the finished part is removed from the mold. If the mounting tab aperture was formed as a cylindrical bore by providing a cylindrical pin-type structure in the mold this could result in problems when removing the finished part from the mold due to the increased frictional forces between the casing and the mold which would result when removing the casing from the mold.
Therefore, the casings are likely to be continued to be manufactured with inner tapered surfaces in the mounting tabs and it would be desirable to provide an improved apparatus and method for mounting the optical element onto a mounting plate.